Czasopismo Techniczne z. 5. Mechanika z. 1-M

Czasopismo Techniczne z. 5. Mechanika z. 1-M

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Collection items (26)


The influence of production process conditions on the rheological properties of pastes

Tal-Figiel, Barbara, Kwiecień, Magdalena, Figiel, Wiesław
Article
2012
Pastes are multiphase systems which are frequently encountered in the food, cosmetics and pharmaceutical industries. Their production is a difficult process, due to their non-newtonian character and also because of limited stability of many active substances which have to be included in the commercial product. Therefore highly intensive and prolonged mixing is not recommended for their production. In this work investigation of process condition influence on the rheological parameters of final product have been carried on. The results obtained using pharmaceutical ointment bases as a test fluids, show importance of the preparation method.

Oxidative coupling of methane: a new process concept for the improvement of the downstream processing by using adsorption

Son, Nghiem Xuan, Arellano-Garcia, Harvey, Wozny, Günter, Tran, Trung Kien
Article
2012
This paper, inspired by the success of adsorptive air separation in big scale (up to 250 tons/day), looks into the possibility of replacing cryogenic distillation with adsorptive separation, and thus improving the downstream processing of OCM. This results in a new process concept. For this purpose, a plug flow model of fixed-bed adsorber was developed and several separation schemes were investigated via simulation. Among them, the simultaneously separation of ethylene and carbon dioxide using zeolite 4A is found realizable. The results show that by switching from cryogenic distillation to adsorption, separation cost can be significantly reduced.

Investigation on membrane-assisted CO2 removal process for oxidative coupling of methane in mini-plant scale

Song, Shankui, Stünkel, Steffen, Godini, Hamid Reza, Son, Nghiem Xuan, Wozny, Günter, Yuan, Jingqi
Article
2012
In this paper the application and the performance of a membrane unit for preliminarily removing CO2 from the product gas mixture in the Oxidative Coupling of Methane (OCM) process based on a mini-plant scale experimental facility are presented and discussed. The model for the membrane unit is validated via experiments based on the comparison of concentrations and recoveries, respectively, with a brilliant agreement

Impact of foam to column operation

Senger, Gerrit, Wozny, Günter
Article
2012
Foam in process engineering can cause severe problems in distillation and absorption towers which may result in heavy operation problems, reduced capacity and reduced separation efficiency. Foaming behavior cannot be described yet analytically or thermodynamically based on physical properties (density, viscosity, etc.). The dimensioning of packed columns for foaming media in chemical industry or flue gas scrubbing (coking plants, carbon dioxide capture, etc.) in the past was afflicted with oversizing by unfounded safety factors. The invented new foam test device is capable to identify the qualitative foam behavior and intensity in packed columns by two experimental tests - based on systematic results of a pilot plant. The packed column adapted test device will help to identify a potential foam problem and allows prematurely taking respective steps in account.

Propane as real alternative to R404A refrigerant in light commercial refrigeration

Sedliak, Jozef
Article
2012
The future and sustainability of refrigeration industry is in high efficiency, low noise and operation with low environmental impact refrigerants. Continuously trend of HCFC and HFC refrigerants phase out opened research of other refrigerants alternatives to fulfill market requirements. Propane as natural refrigerant has high potential to succeed in the field of light commercial refrigeration by replacement of R404A. Thermodynamic properties of propane allow improving compressor performance comparing with R404A alternative. The study presented in this paper is focused on the proper design of discharge valve system of R290 compressors which primarily have been designed for R404A operation. The paper shows noise and efficiency improvements of light commercial compressor using propane that makes this refrigerant very attractive.

Scale-up of mixing equipment for suspensions

Rieger, František, Jirout, Tomaš, Ceres, Dorin
Article
2012
The most of mixing experiments are carried out in laboratory scale with geometrically similar models. To be able to use the results for design of industrial mixing equipment, knowledge of scale-up rules is necessary. Therefore, this contribution is aiming to experimentally verify scale-up rules. The visual method of determination of just suspended impeller speed was used in order to determinate suspension measurements. This method is generally defined as the state at which no particle remains in contact with the vessel bottom for longer than a certain time (approximatelly 1 s). Glass particles with four equivalent diameters dp in range 0.16 and 1.19 mm and volumetric concentration c from 2.5% to 20% were used as solid phase.

Influence of non-ionic surfactants on liquid-liquid mass transfer of single droplets

Paul, Niklas, Kraume, Matthias
Article
2012
One of the main goals of “green chemistry” is: using water as a solvent. Many substances are hardly soluble in water; hence multiphase reactions will not proceed, for instance. By using surfactants the water solubility of such substances can be increased which ends up in an increase of the reaction rate. Due to their amphiphilic structure surfactants adsorb at interfaces. This is the place where the important transport processes occur. Therefore, an interference of the mass transport by the surfactants is obvious. In previous works a reduction of the mass transfer in the presence of surfactants was observed. Also, in this work the experimental results show a decrease of the mass the transfer, but describing this reduction of the mass transfer with the known phenomena from literature is not enough. Additionally, the phase behaviour has to be taken in account.

Energetic and ecological balancing hybrid heating system with renewable energy sources

Pater, Sebastian, Magiera, Janusz
Article
2012
This paper deals with hybrid heating installation for house heating and domestic warm water production used in private house in Batowice (near Kraków). The system consist of four heat sources, including three renewable energy sources: brine-water heat pump with three vertical boreholes, a fireplace with a water jacket and heat exchanger, heat pipe vacuum-tube solar collectors and gas condensing boiler. The integration of all heat sources takes place through a novel, advanced cascade combination of two DigiENERGY control systems, which by registration large number of system parameters and compilation of statistics plays important role in energetic and ecological installation balancing. The operational installation results from September 2011 were presented and analyzed.

Development of separation methods for a continuous hydroformylation process in a mini-plant scale

Müller, David, Müller, Michael, Nguyen, Le Anh Thu, Ludwig, Johanna, Drews, Anja, Kraume, Matthias, Schomäcker, Reinhard, Wozny, Günter
Article
2012
In this contribution a novel process concept for the continuous hydroformylation of long chained alkenes to aldehydes in micro emulsion mixtures with the aid of a hydrophilic rhodium−ligand−complex catalyst is discussed. The challenging aspects with regards to the technical and economic feasibility of the process concept are the separation steps to recycle the expensive catalyst. To investigate and optimize the described process concept, a mini-plant is built at the Berlin Institute of Technology. Due to the lack of thermodynamic data, the design of the crucial separation steps, decanter and micellar enhanced ultrafiltration (MEUF), strongly depend on experimental data. Therefore, “small scale” experiments are designed with adequate similarity to the actual units in the plant. The information gained therein leads to improvements for the separation steps and helps to determine operating parameters for the mini-plant.

Time-averaged velocity profile model of drag reducing polymer solutions in the turbulent pipe flow

Matras, Zbigniew, Kopiczak, Bartosz
Article
2012
The qualitative, theoretical analysis of macromolecular polymer additive effect on abnormal deformation of the velocity profile of the polymer solution flowing in turbulent motion in smooth pipes of circular cross section is presented. Comparison of the substitutive velocity profiles built in the work shows that for the laminar flow polymer additives do not affect its shape. For the turbulent flow time-average, dimensional velocity profile is always more extended comparing to its Newtonian or purely-viscous equivalent at the same Reynolds numbers. The results suggest that this phenomenon increases with increasing values of the characteristic time constant λ, representing viscoelastic properties of the solution, and with decrease in the diameter of the pipe where the flow is performed.